Apparatus for separating suspended particles from gases



c B. MCBRIDE ETAL 2,632,527

APPARATIjS FOR SEPARATING SUSPENDED PARTICLES FROM GASES Filed Aug. 5, 1950 March 24, 1953 & 970% v Arm//va Patented Mar. 24, 1953 V APPARATUS FOR SEPARATING SUSPENDED PARTICLES FROM GASES Charles B. McBride, Portchester, N. Y., and Philip F. Best, Riverside, Conn., assignors to The Thermix Corporation, Greenwich, Conn., a

poration of Connecticut Application August '3, 1950, Serial No. 177,367

' tubes "have been arranged in a plenum chamber to which the dust laden gas was supplied. The. gas necessarily came into contact first with those tubes nearest the point of supply and, finally, that portion of the gaswhich had not entered these tubes entered the tubes farthest from the point of supply. With such anarrangement a tendency for variation in pressure between different tubes, or tubes in different parts of the apparatus, was

inherent with a consequent danger of unequal working of the tubes and re-entrainment of dust. Measures were adopted to overcome this tendency as much as possible by making a plenum chamber that diminished the direction of flow toward the more remote portions and, accordingly, making the off-take pipes from the centrifugal separating tubes of different lengths, being longer, to pass through those portions of the plenum chamber of greater height or cross-sectional dimensions.

Centrifugal apparatus of the above type was also used in connection with electric separators to give a preliminary separation of the suspended particles before passing into and through the electric precipitators. This involved another problem of again bringing the partially cleaned gas leaving the centrifugal separating apparatus into a uniform non-turbulent flow desirable for electric separators.

In our present invention We provide an arrangement of centrifugal separating tubes in which the necessity for the dust laden gas to pass a large number of tubes to reach certain more remote tubes is avoided and in which the gas passes through the apparatus with a minimum of pressure drop and with a uniform undisturbed flow.

In our invention'we provide a supply chamber through which the gases flow toward the rear of the chamber. Immediately in advance of the rear wallof the chamber a number of separating chambers are provided with their side walls spaced from the opposing side walls of adjacent separating chambers and from the side walls of the supply chamber so as to provide passages, one on each side of each separating chamber.

The separating chambers are divided by a vertical partition spaced in advance of the rear wall of the supply chamber so as to divide each sepa rating chamber into a plenum chamber between Claims. (Cl. 183-80) cor- 2 the partition and the rear wall of the supp y chamber and a dust chamber in front of the plenum chamber.

Inlets are providedon each side wall of the plenum chamber to admit the particle carrying gases from the passages between the separating chambers so that gas mayjenter equally from each side. 4 In the partition 'Wall are mounted groups of centrifugal tubes, each receiving the particle laden gasesfrom the plenum chamber through rotatory inlets which give the gases a whirling movement to project the particles forwardly throughthe" open end of the inlet into the dust chamber. The clean gases are withdrawn through outlet pipes which project into their respective centrifugal tubes from the rear wall of the separating chainher to form annular spaces in the centrifugal tubes into which the rotating gases are received from the inlets. The gases from which the dust has;

been thus centrifugally separated pass through the outlet pipes and through the rearwall of the supply chamber either to'atmosphere or to an electric precipitator.

The separating chambers may be maderela tively narrow so as to have but a few vertical rows of tubes as, for example, five, so that the particle carrying gases need pass but two tubesto reachthe rearmost one from each side. Consequently, there is no appreciable difference in pressure or distribution conditions for the centrifugal tubes and no substantial tendency for differencesin pressure in the tubes or dust chambers to cause re-entry of the gases from the dust chamber and, re-entrainment of the separated particles, j The outlet pipes from the centrifugal tubes, are accordingly distributed uniformly throughout the area of the rear wall of the supply chamber. The gases delivered through the outlet pipes are, therefore, substantially uniformly delivered, and with uniform pressure conditions; They flow without disturbances or turbulence from the rear wall of the supply chamber and are thereby suited for immediate precipitation. Such an electric precipitator may be placed immediately back of the rear Wall of the supply chamber. 7 This results in a very compact arrangement of the preliminary centrifugal separator and the electric precipitator. H In the event that the gases may carry larger or more massive particles, these may be thrown out in the passages by extending the passages between the separating chambers to the rear of the inlets to the plenum chamber andprovide a battle on which these particles may be caught.

The various features of the invention are illus trated in the accompanying drawings in which Fig. l is a vertical section of a centrifugal separator and centrifugal tubes embodying the invention, certain parts of the tubes being broken 5 away to :show thecerotatory passages;.-

Fig. 2 .is.a rhorizontal section-through thexcene trifugal separator showing the direction of flow;

Fig. 3 is a vertical section on the line 33 of: Fig. 2.

The centrifugal separatoras" shown: in: the; drawings comprises a chamber I3 through which the gases are delivered andi-pass towardjameari wall [4. Immediately in advance ofrtheerearzr wall are provided a numberofiseparating cham thati thei gases ema-yfflow from: each side. intdthe.

reaniportion of; the-rseparating. chamber.

Each-separating; chamber is divided, i as shownmorei-clearly; in @Fig; 1., by.- a" substantially verticalpartition-J2+ in :advanceofthezwall v Hlcintov a.

plenumrchamben 22 and-=audust-collecting cham ber utimmediatelytin advance; :of the: plenum chamber.

As -shown in Fig; 1 .the. wall 21- is @of .a steppedz. construetionshavings{aces1 slanted alternately in:-

opppsiteidirectionss The partition- :mayshowever: 401

bee-straights Groupsfi of centrifugaL- separating: tubesazbarer mounted in the partition. 21 and: project forwardlysan-d preferably downwardly-rinsto the dust collecting chamber 2 Theses-tubes mounted: in them-rear wall. I deco eaxiallywithiits respective) centrifugalrtube. 24-andiopen atuboth. ends.

T-heoffrtake pipes .extend into .thecentrifugal.-

tubesior-a. distanceshortof the. length of said;

tubes; ass shown. in: the. partly broken =emvewrtube. ofilifig. .l toiformramannular spacei 6.:into. ,.whichi the: gases-are; delivered; fromlthe plenum; chama bersl'Lthrouglrthe rotatory inlets. ofaany suitable;-

type: 5 5K In.the'ispecificirormshown inTE'ig. 1...these .rotatony. in1ets+may. be. formed;- byz-portions ,.ol:, the. wallI2-L cut-andbent-latan .angleinto-the annular; space 2B.Lso.as..to..-form. inclined .gnide vanes 2-?! aboutnthe -off-.-take.pipe.25.. The dustuladen gasesl 6O suppliednto the rplenumichamber therefore, flowthroughr the rotatory. passages with v a continuous, whirling movementlthrough the annular passage,

2 6;.the. momentum. of .theparticIes throws them. forwardlyth'rough the forward vopenaend .;of.. the. centrifugalltubes into. the. dust. chamber .13 while. the. direction. of. mo,vement..'of the. gases isre: versed'andipass outwardly, through theofietake. pipes 25'.

The; separating chambers may be made, as

narrow: as.desired,,but-'when made ofi'a dimen.. sion to takex five. sidewise spaced verticalirows oiltubes; leach t'ubeiisi quite; close. to..-the.. inlet; openings. The. second.'row. oitub'esifromreachr one row of tubes. The middle row is supplied with gases which pass two rows of tubes but is supplied from each side. As a consequence pressure conditions throughout the width and height of the plenum chamber are substantially uniform witha-minimumof changessinrpressureg Flow conditions,gthrough .thenacentrifugal tubes are correspondingly equalized so that there is a minimum tendency for unequal pressures in the dust chamber to cause re-entrainment. Also the "off-take pipes are spaced substantially uniform-1y," which combines with the uniform deliverymfrthe gasqfromxeach ofi-take, producing a uniform;distribution of flow to the centrifugal separatingzunit: I l

Suitable-edust:receiving hoppers 28, 29 and 30 areproyided. respectively for the dust collecting chambers 23"and'the precipitating units II and I22.

The particle carrying: gases flow toward the rear. wall 1.4g of: thedelivery chamber. with: in-

creased velocity, which is-: imparted; to. ther pare ticles; carried As. the: directions. ofthe-,-gases changes to enter the separating--- chambers. through. the inlets, asillustrated ,at-,3.l v in .Figr12, the. heavier particles: are thrown -by-a their" momentumlrearwardly and maybe received-in evertical. channels .7 32.. formed in. the ,i rearwall: I 4. 1 Inclined bafiies 33 are. provided .-in.-the. channelstocatch'the. particles and .throwthemddwnward ly into; a suitable: happen. 34.

Through the aboveinventionx weshave pro--- vided centrifugal 1 dust. separating ;apparatusin--. which. the gases fiowwitha minimum-of disturbance andipressure drop .toprovideanundisturbed, uniform. stream ,ofi cleanedgas and .inwhich the: distribution tmthecentrifugal .tubes. isldirectand, equal.

It .may be. .noted alsofthatjthaplenumi chameber formed-between .therrear. wall I l and mile-par. titionzL or..3.5,.is,narrow inasmuch-as the flow through. this plenum ,chamber is fen-only short distances and,-, .consequently the; off-take; pipes; Ziand 39,.may, bemadepfl minimumlengththus. saving in the quantity, of. pipe. requiredend in; frictional losses.

Having. described;our.,invention, .What wezclaim 1s.:.i

l-aApparatus for. separatingsuspended: par.- ticles. from a gas. whiehcomprisesasupplychameher. having; anerectrearwall, separatingcham bers extending forwardlyt oi-.-said,rean wall; and; spaced sidewise to; provide. aspassageat-eachside1 ofi. each chamber-4: al-partitions.in;each;separating; chamber spaced from said rear wall todivideeachi said -.chamber into. a plenum compartment, between said partitionand said .wallihaving an inlet,- fromeach of the 4 passages; onopposite sides of. said separating chamber, anda, .dust collectingcompartment-in advance-of said plenum; chamher and. separating elements for-eachz-separating chamber eachcomprisinga:centrifugalitube mountedlinrsaid:partitionand; extending into and opening into saidrdustchamber; an open-gended off-takepipe insaid rear walland-extendingjnto its-respective centrifugal-tube-to form-an annular; space therein and rotatoryinlets fromisaid ple-- num chamber to said annular spaces;

2. The apparatus: of claiml, in: which; said" rear: wall; has a vertical channel -aligned; with each said passage and; vertically spaced; bafiles; inrsaid channels.

3. The apparatus of claim '1 in which said separating chambers are converged-forwardlyto.

side, ismsuppliedlwithgases .whiizhneed pass-but ;v n ovideleonverging mletstosaid. passages,

4. The apparatus of claim 1 in which said partition is alternately inclined in vertical sequence in opposite directions and in which said separating elements are mounted in said inclined surfaces at a right angle to the lengths of said elements.

5. The apparatus of claim 1 in which the partition is slit to form inclined vanes into the annular space between each centrifugal tube and its respective outlet pipe.

CHARLES B. MCBRIDE. PHILIP F. BEST.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number 15 402,693

6 UNITED STATES PATENTS Name Date Soyez et a1 Apr. 9, 1935 Schmidt Dec. 30, 1941 Danz July 6, 1943 Allardice Aug. 24, 1943 Scheineman Dec. 28, 1943 McBride et a1 Oct. 1'7, 1944 Pootjes Mar. 27, 1945 Watson et a1 June 14, 1949 Yellott Jan. 29, 1952 FOREIGN PATENTS Country Date Great Britain Dec. '7, 1933 Great Britain Sept. 25, 1946 

